Many battery powered communication units have a sleep mode in which they are able to conserve power by powering down components such as their receivers. These communication units then “wake up” periodically to determine if any messages (pages) are going to be transmitted to them. If there are no messages that the communication unit needs to receive, it will power down in order to extend its battery life. Next generation Code-Division Multiple-Access (CDMA) cellular communication systems, more commonly referred to as CDMA 2000 or Wideband CDMA systems, incorporate such power saving techniques. Each communication unit within a CDMA 2000 system is normally able to determine to which group of four, 20 millisecond (ms), synchronous frames on its paging channel (PCH) it is assigned. This group of frames, referred to as its “paging slot,” is used by the infrastructure to transmit messages to the particular unit. Thus, a communication unit in so-called “slotted mode” operation exits its sleep mode in order to monitor transmissions associated with its assigned paging slot. The more quickly a communication unit can determine that it has no messages or no more messages to receive, the more quickly it can return to sleep mode and conserve power, further extending its battery life.
The communication unit marketplace today is extremely competitive. Consumers demand units that offer the longest talk-time with relatively infrequent recharging cycles, i.e., with longer battery lives. Thus, a communication unit, a communication infrastructure, and method that extend battery life by enabling the communication unit to perform this determination more quickly are needed.